We intend to concentrate our efforts on linkage and selection theory, theory of cultural transmission and natural selection, and ascertainment of the consequences from the nature of population structure and selection interaction. On linkage and selection we shall be partly concerned with analytical and numerical studies of random selection with multiple loci and multiple alleles. The main effort will be directed toward developing a useful classification of selection regimes, levels and forms of epistasis, relevant parameterizations of the recombination process and the introduction of suitable descriptive procedures for the evaluation of gamete frequency configuration data with objective to the interpretation and meaningful association among these components. Apart from its independent value, the study of selection and recombination in the multilocus context is germaine in securing a deeper understanding of the dynamics of quantitative and polygenic inheritance. The cultural transmission models are to be extended to include certain developmental stages and an analysis of correlations between relatives. For the discrete phenotype model we will include transmission by contagion -- an epidemic form of acquisition of the phenotype. We will also pursue more elaborate population structures through modeling and data analysis in order to secure comparisons and contracts in appraising the influence of different population structures and patterns of migration flow as contributing to the maintenance of polymorphism and their environmental and ecological correlates. BIBLIOGRAPHIC REFERENCES: Karlin, S. (1976) "Population subdivision and selection migration interaction," proceedings of Population Genetics and Ecology, Acad. Press, N.Y.: 617-657. Karlin, S. and Richter-Dyn, N. (1976) "Some theoretical analyses of migration selection interaction in a cline: A generalized two range environment," proceedings of Population Genetics and Ecology, Acad. Press, N.Y.: 659-706.